Magnetic cleaning device



A y@ Us lm c. w. v. DAVIS 2,415,730

NAGN'ETIC CLEANING DEVICE Filed Feb. 8, 1943 v l v Patented Feb.v 11, 1947 UNITED STATES' MAGNETIC CLEANING DEVCE Charlesl William Verity Davis, London, England, assigner to The Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application February 8, 1943, Serial No. 475,227 In Great Britain February 20, 1942 (ci. -1o4)' 3 Claims. l

My invention relates to magnetic cleaning devices particularly applicable for cleaning and/or removing magnetic particles from dicultly accessible regions.

It has been proposed to recover articles or fragments of magnetic material from inaccessible regions by the use of magnets. Magnets of conventional construction are however not well adapted for removing magnetic dust, chips, and the like from regions such as internal screw threads or from within cylindrical borings.

The object of the present invention is to provide a magnetic cleaning device which is suitable for such purposes and which is generally useful for cleaning articles madeA from or superflcially contaminated with magnetic material.

According to the invention use is made of a wire brush, the wires being of steel or other magnetic material having stiness and spring in accordance with the work to be performed 'by the brush but of -low magnetic retentivity in comparison with magnet steel; the Wires of this brush are anchored in a mount whereby the brush is secured to a holder accommodating or consisting oi a magnet; the ends of 'the wires may abut directly against one pole face of the magnet. The magnet is preferably a, permanent magnet but may be an electro-magnet energized from a suitable source located either externally or positioned within the holder. The holder itself is provided with a grip or a handle of convenient length in accordance with the nature of the work. The device can then be used as a wire brush and in addition to the normal brushing action, magnetic particles even in otherwise inaccessible positions will be picked up by the magnetic attraction of the steel or like wires. Preferably the brush is detachably secured to the holder, so as to enable easy replacement of a worn brush or substitution of a Vbrush of different shape or character. With such a detachable brush, the magnetic particles picked up by the brush can readily be removed when the brush is detached-the magnet remaining in the holderand the magnetisation being operative and inoperative positions as required.

Similarly, when using an electro-magnet demagnetisation of the brush may be obtained by opening the energizing circuitl of the electro-magnet.

The holder for the magnet may be made of brass, hard rubber or other non-magnetic material, and may be provided at one end with an internal screw thread or other means for the attachment of a handle. At the other end, the brush is attached in a convenient manner. Thus. for example, the bristle mount (similarly of brass, hard rubber, or other non-magnetic material) may be provided with an external screw thread for engagement, with an internal screw thread in the holder; alternatively a bayonet type joint can be used.

The ends of the wire bristles which abut against the magnet are ground or otherwise machined to lie in a at surface, and the end of the magnet is correspondingly flat so as to ensure good magnetic contact. The pressure between the abutting surfaces can be maintained by means of a spring operating on the magnet and tending to urge it towards the brush.

The wires of the brush areanchored in their mount preferably by soldering or brazing when a metal mount is used, but any suitable cement can be employed and in some cases use can be made of welding.

The invention will be further described with reference to the appended drawing showing some constructional forms of magnetic brushes in accordance with the invention. The brush shown in Fig. 1 comprises ahandle-holder I0, a magnetic actuating element II, and cleaning bristles I2. Holder I0 consists of a hollow brass tube closed at one end by means of an integral apertured wall portion I3, and internally threaded at its other end as shown at It.

The magnetic actuating element I I consists of a rod-shaped permanent magnet loosely positioned within the holder l0 and retained therein by means of a pin member I5 which is secured to one end of the magnet and extends through and has for a Abearing the aperture of the wall portion I3. At its protruding end the pin l5 is formed with an integral ball-shaped collar I6 adapted to engage a socket consisting of two resilient metal clips I1|1 xedly secured to the outer surface of the Wall I3. For facilitating axial movement of the pin I5 its protruding end is formed into an integral collar I8 which serves as a handle for grasping the pin.

The bristles I2 consist of a plurality of Wire elements of steel having their ends embedded in a mounting disc 2|) of brass. Disc 20 is provided with external screw threads i'or engagement with the internal screw threads of the holder IIJ. As'

shown, the bristles |2 extend to the inner surface of the disc 20 so as to abut against the adjacent pole face of the magnet, a pressure contact between the pole face and the ends of the bristles being provided by a compression spring 2|.

In the brush shown in Fig. 2, the handle 23 is attached to a separate magnet housing consisting of a brass tube 25 internally threaded to receive iron pole pieces 26, 21 which are screwed into the tube 23 and clamp between them the hollow cylindrical permanent magnet 24. The pole piece 26has a tapped hole to receive the handle 23 while the pole piece 21 has a. tapped hole 28 to receive the brush proper, which may be of -the same form as the unithl2, 20 of Fig, 1.

In the construction ofiFig. 2, however, the

'bristle mount 20 (see Fig. 1) should .be of magnetic material.

In Fig. 3, the magnetic bristles 35, 36 are set on the peripheral surface of a brass sleeve 33 within which the cylindrical magnet 32 is housed. The handle 3| screws into the magnet 32, has a shoulder forming an abutment for one end of "the sleeve 32. The other end of the sleeve is held by a retaining bolt 34 vscrewing into the end of the magnet 32 remote'vfrom the handle. The bristles are conveniently set in helical rows and in the drawing twohelical rows 35, 36 are shown. Naturally any desired number of helical rows can be provided. The magnet 32 may with advantage be magnetised with consecutive poles arranged along the longitudinal axis of the magnet so as to form in eiect a plurality of individual magnets placed end to end with like poles adjacent to each other.

Fig. i shows a brush similar to Fig. 3 but in which the magnet is replaced by a plurality of magnets placed end to end with like poles adjacent. The brass sleeve 33 is provided with radially extending bristles 35, 36 arranged in helical rows as in Fig. 3. The handle 3| has a tlireaded extension 38 which'passes through the sleeve 33. The magnets 32a, 32h, 32o are in the form of hollow cylinders. Interposed between adjacent magnets are spacing washers 31 o! fibre or other suitable non-magnetic material. 'Ihe magnets and the sleeve are heid in position by a nut 39, screwing on the threaded end o the rod-like extension 38.

While I have described my invention in speciic embodiments and by means of specific examples I do not wish to be limited thereto for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.

Iclaim:

1. A magnetic cleaning device comprising a hollow tubular bristle mount having a wall, lbristles of magnetic material of low magnetic retentivity anchored at one end in the wall said bristles projecting radially outwardly, and a permanent magnet positioned within said bristle mount.

2. A magnetic cleaning device as claimed in claim l, in which the permanent magnet exhibits poles lengthwise of the tubular mount.

3. A magnetic cleaning device as claimed in claim 1, in whichthee tubular mount accommodates a plurality of permanent magnets arranged end to end with like poles adjacent.

CHARLES WILLIAM VERITY DAVIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS British Apr. 19, 1934 

